He was also billed as Sen Yung, Sen Young, Victor Young and Victor Sen Young.
No explanation was given for his character changing from Jimmy Chan to Tommy Chan.
His role on Bonanza was stereotypical as he provided comic relief with broken English dialogue.

Why he might not be annoying

He was a salesman for a chemical company trying to get 20th Century Fox to purchase a flame-retardant compound when he was urged to audition for 'The Good Earth.'
He joined the US Army Air Force during World War II, rising to the rank of captain.
He was shot and wounded during the hijacking of a Pacific Southwest Airlines plane he was a passenger on (1972).
He was talented cook who authored 'The Great Wok Cookbook' (1974).
A scholarship was established in his name at the University of California, Berkeley, where he had majored in animal husbandry.

For 2019, as of last week, Out of 2 Votes: 0% Annoying
In 2018, Out of 3 Votes: 33.33% Annoying
In 2017, Out of 8 Votes: 62.50% Annoying
In 2016, Out of 1 Votes: 0% Annoying
In 2015, Out of 14 Votes: 14.29% Annoying
In 2014, Out of 11 Votes: 63.64% Annoying
In 2013, Out of 16 Votes: 43.75% Annoying
In 2012, Out of 17 Votes: 23.53% Annoying
In 2011, Out of 9 Votes: 66.67% Annoying
In 2010, Out of 17 Votes: 23.53% Annoying
In 2009, Out of 85 Votes: 37.65% Annoying